1. Field of the Invention
The present invention relates to a process for preparing amine-terminated compounds. More specifically the present invention relates to a solvent-free process for preparing amine terminated compounds by reacting polyfunctional acetoacetic acid esters with ammonia or primary amine containing compounds.
2. Brief Description of the Prior Art
The art known processes for the preparation of amine-terminated compounds by reacting polyfunctional acetoacetic acid esters with ammonia or amines, invariably, involves the use of solvents. U.S. Pat. No. 3,691,112 (and the corresponding German Offenlegungsschrift 1,935,484) describes the preparation of compounds by reacting a polyfunctional acetoacetic acid ester with ammonia or an aliphatic or aromatic primary or secondary monoamine. The reaction is conducted in the presence of a solvent (hydrocarbons, such as benzene and toluene, and halogenated hydrocarbons, such as chloroform and carbon tetrachloride, are disclosed) and a catalyst. Suitable catalysts are described as "acids, for example hydrochloric acid, formic acid or glacial acetic acid, or other compounds such as iodine, cation exchangers or active alumina."
U.S. Pat. No. 3,666,726 (and the corresponding German Offenlegungsschrift 1,935,485) describes the preparation of similar compounds by reacting a polyfunctional acetoacetic acid esters with aliphatic aminoalcohols or diamines of different reactivity towards acetoacetic acid esters, e.g., those which contain primary and secondary or, alternatively, aliphatic and aromatic amino groups in the molecule. All of the diamines disclosed contain at least one aliphatic amino group. The reaction is conducted in the presence of a solvent (hydrocarbons, such as benzene and toluene, and halogenated hydrocarbons, such as chloroform and carbon tetrachloride, are disclosed) and a catalyst. Suitable catalysts are described as "acids, for example hydrochloric acid, formic acid or glacial acetic acid, or other compounds such as iodine, cation exchangers or active alumina." The reference does not describe the use of any specific polyamines where the amino groups are all directly attached to aromatic groups.
Commonly assigned U.S. application Ser. No. 07/562,293 discloses a process for preparing amine terminated compounds by reacting a polyfunctional acetoacetic acid ester with either ammonia or an organic compound which contains one or more primary amino groups in the presence of a solvent and an acidic catalyst selected from the group consisting of (i) boron trifluoride etherate and (ii) organic acids having pKa values of from 0.1 to 0.8.
By this invention, there is provided a solvent free process for preparing amine terminated compounds.